@Dr. Abdelaziz:
Thanks for your question. Unfortunately, there is no straightforward answer to your question. The poultry producer should decide that himself.
In my opinion, enforcement of biosecurity measures for broilers (short life span) may be easier than layers and breeders and in this case you will not be in need for many types of vaccination, but I know the field situation in Egypt which is not different from other develping countries.
Vaccination (as it will be mentioned in my next article in this forum) helps to decrease morbidity, mortality, virus excretion and transmission limiting the economic losses of the disease. Vaccination of broilers with inactivated vaccines in endemic areas is really questionable. First you have to be aware that maternal immunity will mostly interfer with vaccination (according to the vaccination schem) at early age of life (10 to 15 day-old), secondly full protection will be expected three weeks post vaccination. In other words, maternal immunity will protect young birds for at least ten days (according to the vaccine used in breeders), but you will have a gap for at least two weeks until the inactivated vaccine elicits protection. Then, you will have clinical protection until marketing (2 weeks). Therefore, if you already succeeded to prevent introduction of the virus till day 21 or 24, I guess you can do that for the last two weeks; but you never know when the infection occurs.
@Dr.Farook Kahloon:
This is the first article on control of AIV in poultry. In the next weeks, five articles will be published here in Engormix. Each article will throw the light on an intervention tool for the control of the disease in poultry and will discuss the advantages and disadvantages of each one.